Alcatel Carrier Internetworking Solutions Omni Switch/Router - Manual (Page 820)

Controlling IPX Type 20 Packet Forwarding
Page 27-32
Controlling IPX Type 20 Packet Forwarding
The ipxtype20 command is used to control the forwarding of IPX Type 20 packets. The default
setting is to not forward IPX Type 20 packets. You can use the ipxtype20 command to explic-
itly enable the forwarding of Type 20 packets for individual interfaces routing IPX traffic.
Type 20 packets contain the value 20 (14 hex) in the “packet type” field of the IPX header.
Novell has defined the use of these packets to support certain protocol implementations, such
as NetBIOS. As these packets are broadcasted and propagated across networks, the addresses
of those networks (up to 8) are stored in the packet’s data area.
The reason why forwarding of Type 20 packets is normally “off” is that they can cause prob-
lems in highly redundant IPX networks by causing what appears to be a broadcast storm. This
problem is aggravated whenever misconfigured PCs are added to a network.
Follow the steps below to enable IPX Type 20 packet forwarding on a given interface.
1. Enter ipxtype20 .
A screen similar to the following displays:
Do you want to see the status of IPX Type 20 packet forwarding?
(y or n) (y) :
2. Enter a y at this prompt (or press <Enter> ) to display the current handling of IPX Type 20
packets on all configured IPX interfaces.
A screen similar to the following displays:
GP:VL Type20 Packet Forwarding
------- --------------------------------------
3:1 off
4:1 off
group:vlan () :
3. Enter the Group and VLAN numbers associated with the IPX interface for which you wish
to enable Type 20 packet forwarding. For example, you could enter 3:1 .
A screen similar to the following displays:
Currently, Group 3:Vlan 1 has IPX Type 20 packet forwarding off.
“on” or “off” (off) :
4. Enter on to turn IPX Type 20 packet forwarding “on” for this interface. The default is “off”.
A screen similar to the following displays:
IPX Type 20 packet forwarding on 3:1 has been changed to on.
You may also elect to bypass the above prompts. To do so, simply include the Group and/or
VLAN number and the word “on” (or “off”) as part of the command line.
For example, to turn forwarding “on” for Group 4, VLAN 1, enter ipxtype20 4 on.
A screen similar to the following displays:
IPX Type 20 packet forwarding on 4:1 has been changed to on.
If you enter the ipxtype20 command with options for an interface that is not configured for
IPX, a message similar to the following will appear:
Group 1:Vlan 1 isn’t configured for IPX.
Usage: ipxtype20 [group:vlan] [on | off]